The present invention relates generally to anti-skid control systems for use in motor vehicles, and more particularly to such an anti-skid control system arranged so as to optimally determine the initial target braking hydraulic pressure at the time of start of the anti-skid control.
Known is a braking apparatus with a hydraulic pressure braking device in which in order to keep the slip ratio of a vehicle wheel to the vicinity of a predetermined value, a target braking hydraulic pressure is calculated and the hydraulic pressure supplied to the hydraulic pressure braking device is controlled to become equal to the calculated target value. In such an anti-skid control apparatus, the initial target value is determined to assume the hydraulic pressure in the hydraulic pressure braking device at the time of start of the anti-skid control; that is, the target hydraulic pressure thereafter is successively calculated on the basis of the hydraulic presure therein on the start of anti-skid control, resulting in taking a long time to bring the hydraulic pressure to the optimum value. Furthermore, due to the time lag on response, the hydraulic pressure in the hydraulic pressure braking device reaches the target hydraulic pressure with overshooting so that the wheel speed is rapidly decreased for a time period from the start of control and then settled to assume a desirable slip ratio with undershooting, resulting in uncomfortable ride of the motor vehicle.